Current devices to relieve the symptoms of glaucoma are usually based on lowering intraocular pressure (IOP). The latter is especially prone to fluctuations and is often high in patients. These patients are forced to constantly monitor their IOP, with the biggest problem being the timely administration of antihypertensive drugs at the correct dose. Therefore, South Korean researchers have developed a new 2-in-1 smart lens that allows real-time monitoring of IOP and injecting a dose of medication adapted to the pressure level in the patient’s eye. This fully autonomous technology paves the way for a new generation of theranostic smart lenses (combining therapy and diagnostics).
Glaucoma is a chronic eye disease that is manifested by fluctuations in the mechanical pressure inside the eye. In patients suffering from this disease, the outflow of aqueous humor is difficult, which leads to an increase in intraocular pressure. This condition progressively damages the optic nerve and reduces the ability to see peripherally, leading to blindness in the most severe cases.
Currently incurable, currently available treatments only alleviate the symptoms of the disease. Since elevated IOP is the main manifestation of the disease, doctors usually prescribe ophthalmic antihypertensive drugs (eg, timolol-like drugs) to patients. But since the internal pressure of the eye in glaucoma is subject to fluctuations, patients are forced to measure it throughout their lives.
Unfortunately, modern devices for monitoring IOP are either available only in the clinic or available at home, but require certain skills on the part of the patient. In addition, it is not easy to collect a lot of measurement data in order to properly assess fluctuations in IOP. This difficulty can lead to incorrect dosage of the administered drug. In addition, each patient has a different therapeutic profile. Thus, the ability to read IOP data in real time will greatly improve the daily life of patients.
In a new study published in the journal Nature Communications, researchers at Pohang University of Science and Technology (POSTECH) in South Korea propose a smart lens that can detect intraocular pressure in real time and deliver an appropriate dose of medication. Namely, that smart lenses for glaucoma patients already existed, but only controlled IOP. Then the drugs had to be administered separately, in the form of eye drops. However, this manual instillation can lead to dosing errors as well as time constraints. POSTECH’s new 2in1 lens offers an alternative that provides improved comfort and accuracy for patients.
Super flexible control system
Theranostic contact lenses have a built-in sensor made of hollow gold nanowires. The latter is connected to the drug instillation system, as well as to the power supply and wireless communication system. Everything is coordinated with an integrated circuit chip designed to monitor and control the IOP.
In tests on rabbits (who had glaucoma symptoms), the lens was highly effective in detecting pressure fluctuations. The drug delivery system has also shown great flexibility in measuring and delivering the exact dose needed for each level of internal pressure increase. In addition, the material used by the researchers is chemically stable and biocompatible.
Flexibility and precision thus allow individual, real-time treatment for each glaucoma patient. In addition, the lens feedback system could be used as a “futuristic self-help platform for glaucoma and other eye diseases,” the researchers conclude in their study.